


yakusoku // promise

by honeyhinata



Category: Shingeki no Kyojin | Attack on Titan
Genre: Clingy Levi Ackerman, F/M, Levi Ackerman/reader - Freeform, Manga & Anime, Protective Levi (Shingeki no Kyojin), Shingeki no Kyojin: Kuinaki Sentaku | Attack on Titan: No Regrets, Shingeki no Kyojin: Kuinaki Sentaku | Attack on Titan: No Regrets Spoilers
Language: English
Status: In-Progress
Published: 2021-01-12
Updated: 2021-01-15
Packaged: 2021-03-16 17:01:30
Rating: Mature
Warnings: Graphic Depictions Of Violence, Major Character Death
Chapters: 3
Words: 4,380
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/28710129
Author URL: https://archiveofourown.org/users/honeyhinata/pseuds/honeyhinata
Summary: Levi Ackerman x Female! Erwin's sister! Reader"If we can meet again. If there is one more chance. Next time, I don't want to lose you again. And I will never lie to you again."They were there for each other ever since the Survey Corps persuaded Levi and his friends to join them. And, at some point, both of them fell in love with the other. Hard, may I add. They vowed to get married someday but in a world where titans roam and death waits at every twist and turn, can they really promise something like that?
Relationships: Levi (Shingeki no Kyojin)/Reader
Kudos: 17





	1. 一 // 01

Y/N narrowed her eyes as she soared through the air using her ODM gear. She was beside her brother, Erwin Smith, as they pursued a trio of troublemakers. 

"Y/N, divert. But remember to keep your eye on the black-haired one," Erwin said. Y/N nodded.

"Yes, brother." Y/N aruptly changed courses, leaving behind her brother and the other three members of the Survey Corps. She skillfully avoided the buildings and watched as the ravenette, whom she was supposed to be watching, jumped out of a window. 

She was about to take action but, before she could, Mike was already on it. He tried to slice the boy's wires but the boy managed to avoid him. Just barely though. 

Y/N locked eyes with Mike and nodded, signaling for him to go after the ravenette. 

Mike whizzed off and Y/N followed after him, prepared to beat the black-haired thug to pulp if he tried anything. 

The thug entered another window and Y/N watched as Mike burst through the fucking stone roof. The blonde tackled the other male and both of them crashed into a pile of wooden crates. The ravenette slid across the dusty ground then proceeded to get back up using a back handspring. Nevertheless, his smooth moves managed to impress even Y/N.

The ravenette grabbed a small knife and attempted to slash at Mike, who dodged the sharp blade. He went to disarm Mike and partly succeeded as only one of Mike's two swords had flung out of the soldier's hands. Just as the younger male went to stab the blonde again, Erwin interfered. 

Y/N took that as her chance to jump down from where she was perched on top of a roof and stand near the fighting pair and behind the ravenette. Erwin pushed the said ravenette into her arms and she easily caught him, placing one of her blades on his throat.

"Stop it," Erwin said, "Take a look around you."

The male's eyes widened slightly and he looked to the side, catching sight of his two friends.

"Let me go you bastard!" The red-haired girl exclaimed, "Damn it all!" 

The other thug with dirty blonde hair directed his gaze from the redhead to the ravenette.

"Levi!" He shouted in shock.

Levi grunted quietly and slowly let go of his knife. Erwin nodded, sending him a small smile of satisfaction. 

"You're quick at reading the situation," Erwin said. Levi didn't reply and continued to glare at Y/N's brother.

"Y/N, keep ahold of him. Don't let go, no matter what you do." Erwin ordered.

"Hai," Y/N muttered. Erwin sighed.

"And drop the sword." Y/N's eye twitched but she followed her brother's command, dropping her blade. Erwin picked it up, smiling, while Y/N clicked her tongue in annoyance.

"Why are we even bothering with them?" She asked.

"You know why," Erwin replied. 

Y/N clenched her jaw. 

"You know why." She mumbled under her breath, mocking Erwin, as she rolled her eyes. Levi snorted.

"He's your leader, right? I don't think you should be mocking him." Levi said. Y/N huffed.

"Not only my leader. He's my brother too." Y/N replied, "I'm only a rank or a few under him though. And three minutes younger."

After that, Y/N kept silent. Levi didn't say a word either as they trailed behind the rest of the group by a meter or two. 

"Y/N!" Erwin yelled from upfront, "Keep up!" 

Y/N's grip on Levi's upper arm tightened as she speed-walked to catch up while Levi reluctantly followed. After all, they also had Farlan and Isabel. And Levi wasn't planning on leaving them behind. Not ever.

"Hah! Take this!" Isabel headbutted the soldier holding onto her and attempted to run over to Levi but Y/N simply stuck out her free hand, catching the other female. "Ack! For a pretty girl, you sure are strong!" Isabel exclaimed. She received no reply though. 

"So, for lunch, I was thinking tacos. How about you Y/N?" Erwin asked, breaking the awkward silence that had settled between everybody.

"Oh god, please no," Y/N said as she handed Isabel over to Mike. 

"Why? I think my tacos are just fine." Y/N snorted at Erwin's comment. 

"No, they are not." She replied.

"I have to agree with Commander Y/N." Cindy (random name), the only other girl scout within the group, said.

"Commander? I thought she was a captain."

"Nah, you're both wrong. She's a section commander."

"No, she's a lieutenant. Get your facts right."

Y/N scowled as her friends and fellow soldiers began to argue about her rank. 

“Oh, for goodness sake! You’re all part of the Survey Corps! Act like it, you nitwits!” Y/N finally shouted, fed up. 

“You heard the lady.” Erwin said, “Be quiet.” 

The group arrived in a clearing that was free of buildings and was basically just dirt. Erwin nodded, ordering Cindy, Y/N, and Mike to handcuff the three underground thugs. 

Y/N forced Levi onto his knees and he grunted in response. She quickly handcuffed his hands behind his back and stepped away. 

“I’ll ask a few questions.” Erwin announced as he stood in front of the trio, “Where did you get this?” The blonde held up a part of the ODM gear. 

He got no reply.

“You guys are skilled with the 3D maneuver gear. Who taught you all that?” 

Still no reply. 

Erwin walked forward until he was standing directly in front of Levi and stared down at him. 

“You’re their leader, right?” Erwin asked, “Were you trained in the military?” 

Levi looked up, glowering at Erwin. 

Y/N, having had enough of it, grabbed Levi’s head, pulled it back, and slammed it into a puddle. Isabel gasped.

”You!” She exclaimed, glaring daggers at Y/N.

Levi struggled under Y/N’s hand. He managed to turn his head to the side so only half of his face was emerged in the dirty water. 

“I’ll ask one more time. Where did you learn to use the 3D maneuver gear?” 

Farlan clenched his jaw.

”Not from anyone! We learned it by ourselves!” He shouted.

“Self-taught, you say?” Y/N asked, raising an eyebrow. She looked at Erwin. “I don’t buy it.” She told him. 

“It’s just so we’re able to rise even a bit in this dirty garbage place! People who’re used to sunlight like you guys won’t understand!” Farlan said. 

Erwin chuckled.

”We won’t understand huh? Well, you can ask my sister over there. She’ll understand.” Erwin said. Everybody turned to Y/N. 

She frowned, gritting her teeth.

“Tch... I was kidnapped and taken here. The person who kidnapped me tried to sell me multiple times. He never succeeded though. In a place like this, I couldn’t trust anybody. So I planned an escape plan with my close friend, Marie. On the day we decided to set the plan into action, my ‘supervisor’ found out and attempted to murder us. He succeeded in killing Marie and, in return for killing my best friend, I injured him severely and used that as my chance to escape. Then I met the scouts and through DNA testing, Erwin and I finally came to the conclusion that we shared the same blood. Thus, making us siblings. And through more tests, we found out we were twins.” Y/N grumbled. 

“And how long were you kept here?” Erwin questioned.

”I was kidnapped when I was one and escaped on the thirty-first of January this year. I spent most of my life down here. So, it must’ve been quite a few years.” Y/N replied. 

Most of the Survey Corps already knew about Y/N’s past so she wasn’t worried about them. What bothered her though is that she was forced to tell her story in front of three thugs who were complete strangers to her. 

“That’s enough! Let Bro go!” Isabel finally spoke up, “Don’t be cocky just because you’re soldiers!” 

Erwin looked at Y/N and she clicked her tongue. Growling, she grabbed Levi by his hair and pulled him up. She kept her hand on his head though, gripping his hair tightly. 

Levi was breathing heavily as Erwin kneeled down in front of him, disregarding the puddle.

“My name is Erwin Smith. And yours is?” Erwin asked.

“... Levi.” 

“Levi... Why don’t we make a deal?” Erwin said. 

“A deal?” 

“I will let your crimes go unpunished. In return, lend me your strength. Join the Survey Corps.” Erwin uttered. 

”And if I refuse?” 

“The military police will have you. Considering all of your crimes, you and your friends, won’t be treated very nicely.” Y/N replied. 

Erwin stood up and started to walk away. He then suddenly stopped and turned around.

”Choose whichever you prefer.” Erwin said. 

“Fine.” Levi clicked his tongue while Isabel and Farlan gasped in the background, “I’ll join the Survey Corps.”


	2. 二 // 02

"They're skilled with the ODM gear. They probably don't need much training with it." Erwin muttered to Y/N.

"But we should still put them to the test. Despite them being low-life thugs, they're important assets to us. Our numbers are limited right now, we can't risk it." Y/N replied.

"I agree. But who'll train them? We're all getting ready for our next expedition. The only free person is..." Erwin trailed off while Y/N clicked her tongue. 

"Absolutely not. I'm not training those brats." She said. 

"Come on Y/N. As you said, our numbers are limited." 

"Tch, fine. But if they die outside the walls, don't put the blame on me. After all, they don't have any experience." Erwin placed a hand on his sister's shoulder.

"Then it's up to you to train them correctly. I'm trusting you with this Y/N. At least make sure one of them survives." Erwin said. Y/N grunted. 

"Tch, whatever." She muttered, looking away. Erwin smiled.

"Good. Now, eat some breakfast. I'll tell the cadets to meet you here in ten minutes." Erwin stood up and exited the dining hall, leaving Y/N alone. She and Erwin had been the only ones left and now that the blonde was gone, only Y/N remained.

She clicked her tongue, as she usually did, and grabbed a stale loaf of bread, biting into it. She didn't know why she had even agreed to teach the newest members of the scouts. But now that she had, she couldn't back out. 

Y/N looked down at her half-eaten bread. She scowled. Her appetite was long gone the moment she thought thinking about those three troublemakers.

"You should finish that." Y/N looked to the side. Isabel was standing there, grinning brightly. Y/N placed the small, half-bit loaf down and stood up. 

"We're going to the forest today." She told the trio that had just recently entered, "Your ODM gear is in perfect condition but it's old. It needs to be replaced. So before we head off, I'll be giving you new gear. Follow me." 

Isabel quickly grabbed Y/N's unfinished bread and clumsily rushed after her.

"You really should finish your breakfast though!" She exclaimed. 

"Don't feel like it," Y/N replied, pushing Isabel away. 

"Man, she's so stubborn." The redhead muttered.

"Why are you even bothering with her?" Farlan asked Isabel. The girl shrugged.

"I dunno. I just, sorta, wanted her to at least eat more." Isabel muttered.

"You should stop feeling that way then." Y/N suddenly butted into their conversation, "Emotions do nothing but get in the way." 

Isabel jogged to catch up with Y/N. 

"How can you say that? If anything, emotions are what make us stronger. Having feelings doesn't make you weak! They are just what make you human." Isabel said. 

"Tch. That's cute. Where did you learn that, a book? Lemme tell ya something kid. Out there is nothing but death. Out there, titans roam. Ya slip up even the littlest bit, congrats, you just died." Y/N didn't say anything else as she walked away, not bothered to wait for Levi and Farlan to catch up.

"Don't bother." Levi grumbled, "She's not going to listen to any of us anyway." 

"Tch, shut up brats. Yer all annoying." Y/N growled as she stopped in front of a door and pulled out a key. She unlocked it and didn't waste a second in kicking the wooden door open. "Gear up. I'm assuming that you know how to and which parts go where and all that crappy shit." Y/N stepped aside and leaned against the wall, "Take more than five minutes and I'll make you train until you drop dead."

"Yesh, hard much," Farlan whispered under his breath. Y/N heard him but didn't comment on it. The trio of underground thugs entered the room and quickly put on their ODM gear. They were surprisingly fast, which shocked Y/N slightly. 

She scowled. She didn't particularly know why she disliked them. She just did. 

Y/N walked into the room, harshly shoving Levi aside. He grunted as her hand came in contact with his shoulder and he didn't hesitate to pull out a small pocket knife, slashing Y/N's palm. The H/C-haired girl wasn't phased though. 

She let the blood drip down her fingers as she, too, grabbed a new set of ODM gear. Her's was starting to rust, which was dangerous if she ventured outside the walls with it.

"The training we'll be doing today is simple. I'll set up some titan dummies in the forest and you try to take down as many as you can. A titan's weak spot is their nape so if you cut that nicely, your chances of surviving are increased by one percent. I don't care how you hold your blades or how you cut, just cut the nape of the fucking dummy." Y/N said.

"But, um... Your hand. It's bleeding." Isabel pointed out. Y/N shrugged.

"A titan can do much worse." Y/N uttered, "Now come on. The sooner we get this training done, the sooner I don't have to deal with you annoying fucks." The trio followed Y/N into the forest and looked around in awe. They hadn't seen many nature-related things so seeing the tall trees were new for them. "You know how to use the gear so I'll leave it up to you. Wait here and don't move." Y/N grabbed the wooden titan dummies, despite them being way taller than her, and used her ODM gear to get around faster. She placed the dummies down in separate spots before making her way back towards Levi, Isabel, and Farlan. 

"You have thirty minutes, good luck," Y/N smirked. 

"W-Wait! How many dummies are there?!" Farlan exclaimed.

"Your time has already started," Y/N said, disregarding his question. Farlan clenched his jaw, annoyed by Y/N's answer. 

"Jeez. You're really obnoxious, ya know that?" He grumbled. 

"Twenty-eight minutes remaining." Y/N drawled. 

"Stop arguing with her." Levi piped up in his usual monotone voice, "We have some titan dummies to slay first." Farlan grunted.

"Yeah yeah, I'm coming." He grouched. Levi zoomed off with Farlan and Isabel trailing behind him. Y/N watched them for a moment before whizzing off after them to make sure that they didn't screw up. 

The female landed on a tree branch and looked below, spotting one of the dummies. She looked around but saw nobody. Y/N rolled her eyes, almost laughing. She wasn't surprised none of them had managed to find the wooden dummy. Sure, that Levi dude had some skills and he'd probably survive most of his expeditions but as for Isabel and Farlan? She'd doubt they'd live past their third one.

A rustle was suddenly heard above Y/N. The H/C-haired girl, on instinct, immediately looked up. She clicked her tongue when nothing happened. It was probably just a bird or a squirrel.

Y/N turned away and was about to zoom elsewhere before a figure jumped down from the tree branch above. Y/N could instantly recognize them, despite her back being to them. Based on how their eyes tried to pierce through her soul, Y/N concluded that it was Levi.

"Oi, Ackerman, there's a dummy down there. Just in case you didn't see it." Y/N grumbled.

"I saw it. I was just waiting for you." Levi said.

"Waiting for me? Why? So you can show off your skills? Let me tell you one thing, Ackerman. Your moves may be impressive but it's nothing Erwin or I can't do."

"You call my friends and me annoying but have you heard yourself? If anyone's annoying here, it's you." Y/N's eye twitched when she heard the ravenette mutter a quiet 'tch'. That was her thing and her thing alone.

"I am your superior, Ackerman. I don't think calling me 'annoying' is showing me the respect I deserve." Y/N growled.

"It's just because of your rank. If you weren't a section commander, a squad captain, or whatever the fuck you are, you wouldn't be able to act like this." Levi talked back. Y/N gritted her teeth.

"If one more word escapes your mouth Ackerman, I'll-" Levi cut Y/N off.

"You'll what?" He asked, smirking. He grabbed Y/N's bleeding hand and lifted it to his lips. 

"What do you think you're doing Ackerman?!" Y/N shouted, enraged. Levi shrugged, gently licking the cut on Y/N's palm. 

"It'll get infected if you don't treat it." He casually said before licking the rest of Y/N's blood, not breaking eye contact with her. Y/N stared at him, her jaw slack. Her cheeks flushed bright red as her mind tried to comprehend what Levi was doing. It wasn't that simple though because even Levi didn't know what he was doing and why he was doing it.

Levi let go of Y/N's wrist after he had finished cleaning the blood with his tongue and smirked at Y/N's flustered face. Her embarrassment didn't last long though, much to Levi's dismay. In under a few seconds, Y/N was back to acting cold and stoic.

"Levi fucking Ackerman. Did you just fucking... lick me?"


	3. 三 // 3

"M, training was a total drag. I couldn't kill any dummies because they had all been slashed to pieces." Farlan groaned. He was walking through the hallways of the Survey Corps base with Levi on his right and Isabel on his left. 

"I only got to kill one," Isabel replied. 

"And I'm guessing you were the one who slashed all the dummies up Levi?" Farlan asked. Levi grunted in response. The dirty blonde-haired boy chuckled. "Man, what a monster. You're a legit beast. I wonder if that would still apply in the bedroom." Levi sent Farlan a disgusted glare, "Oh come on man! There must be someone who's caught your attention!"

Isabel gasped.

"You mean like a crush?!" She exclaimed. Farlan nodded.

"Yeah, like a crush. I'm not gonna lie to you guys, Commander Smith, the female one, is pretty hot. She's big in all the right places and apparently, she hasn't gotten a lover yet." Farlan smirked.

"I'm not interested in her one bit. Her personality is like trash." Levi grumbled.

"OI OI OI! WHAT DO YOU THINK YOU'RE DOING CADET?! IS THIS HOW YOUR MOTHER TAUGHT YOU TO CLEAN?!" Ah, speak of the devil.

"My parents... My parents were killed, Commander... Commander Smith!" The brunette cadet replied, stuttering. 

"And my mother was killed right before my eyes, most of my comrades were eaten by titans in front of me, my best friend died because my squad leader wouldn't let me save her, nobody in my original squad survived except for me. You ain't special cadet. Everybody here has experienced hardships. So start fucking cleaning the floor because you ain't leaving until it's spotless."

"Yes, Commander!" 

Isabel grimaced. 

"You're not wrong about her personality." The redhead muttered, "It's not exactly the best." Farlan quietly groaned.

"We were ordered to kill Erwin Smith but how can we when she's in the way?" He questioned.

"No, we weren't ordered to kill just him. Lovof said to kill both Smiths." The girl muttered, "He said they both prove a threat to him and to take them down no matter what." 

"I can see why she poses a threat to him. She's fucking terrifying." Farlan uttered quietly. 

"Oi Ackerman!" Y/N stormed towards the said ravenette, grabbing the collar of his shirt, "Do you know how to clean?" Levi raised an eyebrow.

"Of course Commander Smith." He replied. Farlan and Isabel watched their interaction, surprised that Levi was letting Y/N touch his uniform. 

"Good. Teach that cadet behind me how to clean. I got places to be." Y/N let go of Levi and was about to walk away. Levi, however, grabbed her by the wrist, stopping her.

"Your hand is still bleeding. Would you like me to l"- Levi was cut off by Y/N bitch slapping his face.

"No, fuck off you brat." She snarled, aggressively spinning around and speed-walking away. Farlan blinked in confusion.

"... What the hell was that man?" He asked.

"During training, the commander's hand was bleeding badly so I licked it to get rid of the blood," Levi said monotonously. 

"Fucking hell man. So you basically drunk her blood?" Farlan sent Levi a concerned look, wondering if his friend was ok. 

"Oh! Like a vampire! Are you a vampire Levi?!" Isabel piped up.

"Not that I know of. Anyway, I have to teach this scum how to clean before Commander Smith yells in my face again." Levi strolled towards the shaking cadet and crouched down in front of him. "... You're stupid." He deadpanned. The cadet blinked.

"... What?" 

Farlan chuckled. 

"He's actually listening to somebody's orders now. That's a surprise." 

"Levi never does that and he hates letting people touch him. Not to mention he would never let somebody's blood even come near him. But now, he's following Commander Smith's orders, he let her touch him, he licked her blood... As weird as that sounds. Does he perhaps... like Commander Smith?" Isabel muttered.

"It's possible. That little shit has never shown any interest in anybody. That is until Commander Smith showed up. I wonder, is she his type? Sure, she's drop-dead gorgeous but I don't think much people could handle her personality." Isabel hummed in agreement with Farlan's comment, "Anyway, it's almost lunch right? We should get going." The pair gave Levi one last glance before making their way past him and the cadet to get to the mess hall. 

The two were about to enter when they spotted the Smith twins also walking towards the mess hall.

"Erwin, as much as I'd love to have Ackerman on my squad, I'm going to have to say no," They heard Y/N say. 

"Y/N, you know as well as me that he's a skillful soldier. Just because you dislike him does not mean you cannot work with him from time to time. With you two on the same squad, it'd be an advantage." Erwin replied. Y/N frowned.

"But Er"- She was cut off by the blonde male.

"No buts Y/N. You know as well as I do that he has potential along with his friends. His friends, however, will be placed in a different squad, mainly because yours is full at the moment." Y/N scowled and huffed.

"Tch. I agree to work with him on missions and shit like that but do not expect me to actually like him or be nice to him." Y/N grumbled, making Erwin smile.

"Wonderful. And, by the way, you should stop making that weird 'tch' sound you always make. Along with clicking your tongue and calling people brats. I believe Ackerman is catching on to your habits and soon enough, you two will act exactly like each other. You already act similar and having someone else with a personality exactly like yours would be stressful." Erwin chuckled as a small growling noise emitted from Y/N's throat. 

"What's so bad about me?" She asked, glaring. 

"I can name many things," Erwin teased, "But I won't. I'm not looking to die at the hands of my sister today." 

And with that, Erwin entered the mess hall. Y/N rolled her eyes and looked at Farlan and Isabel.

"Tch, what are you brats looking at?" She snarled.

"Is it true we're getting separated from Levi?!" Isabel exclaimed. It was already bad enough that she couldn't sleep in the same room as her best friends. Being separated from them would be even worse. Y/N clicked her tongue.

"Yes. It wasn't my choice to make though. Personally, I would've preferred having all three of you on my squad. But that would make thirteen members and that's obviously too big." Y/N muttered before trailing into the dining room after her brother. Isabel sweatdropped.

"So she does care for us, even if it's only a little bit. I guess that's... good enough." The redhead mumbled. 

"It's an improvement at least." Farlan replied. 

Lunch was served and everybody ate in mostly silence. There were a few quiet conversations here and there between some scouts but other than that, nothing else was happening. The painful and awkward silence was finally broken by Y/N when she stood up, her chair's legs scraping across the floor. In her hands was a tray that had a bottle of water, a small loaf of bread, and a bowl of soup that was filled to the brim. What confused everybody though was how she had just finished eating her food. Surely she wasn't hungry anymore. 

Erwin, Isabel, and Farlan did have a theory though. Levi still hadn't turned up and dinner was almost over, meaning if he didn't come soon he'd miss out. And Erwin knew Y/N wasn't in the mood to eat more so there was only one thing she could be planning to do with that extra food.

And that was bringing it to the one and only Levi Ackerman, who she’s supposedly hated. And, believe it or not, that was exactly what she was going to do.


End file.
